Arc lamp



Qct. 20, 1953 Filed Sept. 14, 1950 A. J. HATCH 2,656,482

ARC LAMP 5 SheetsSheet 1 ARTHUR J. HATCH INVENTOR ATTORNEY A. J. HATCH Oct. 20, 1953 ARC LAMP 3 Sheets-Sheet 2 Filed Sept. 14, 1950 FlG-Z ARTHUR J. HATCH INVENTOR ATTORNEY A. J. HATCH Oct. 20, 1953 ARC LAMP 3 Sheets-Sheet 5 Filed Sept. 14, 1950 72 73 NHK ARTHUR J. HATCH INVENTOR ATTORNEY Patented Oct. 20, 1953 ARC LAMP Arthur J. Hatch, Toledo, Ohio, assignor to The Strong Electric Corporation, Toledo, Ohio, a corporation of Delaware Application September 14, 1950, Serial No. 184,837

Claims. (Cl. 31463) My invention relates to are lamps, and the principal object of my invention is to provide mechanism effective to maintain the are both of proper quality and substantially at a prede termined location.

In the drawings accompanying this specification and forming part of this application I have shown for purposes of illustration what I now consider to be the best mode of carrying my invention into practice, and in these drawings:

Figure l is a side view of an arc lamp incorporating the within described embodiment of my invention, but omitting the near side door of the lamp to afford a view of part of the interior of the lamp;

Figure 2 is a plan view of a portion of the in terior of the lamp of Figure 1;

Figure 3 is a diagrammatic representation of the mechanical and electrical arrangements; and

Figure i is a further View of the particular light-responsive means herein shown and described.

My in ention is especially applicable to are lamps of those types wherein the lamp comprises one or more reflectors or lenses or the like, constituting with the are an optical system designed to produce a desired light formation, wherefore it is necessary that the are be maintallied substantially at a predetermined location, in order to maintain proper coordination beween the arc and the remainder of the optical system.

Commonly such lamps are designed for operation on direct current, and to produce the great preponderance of the light at a crater in the end of the positive electrode, and to utilize particularly the light emitted from the crater, and in such instances maintaining the arc in proper coordinatin with the remainder of the optical system obviously is a matter of maintaining the crater of the positive electrode substantially at the predetenined properly cooperating position.

According y although invention is not limited thereto, 1' have here illustrated it in respect of a lamp of the above recited characteristics, and therefore as functioning to automatically maintain both proper spacing of the electrodes and the crater of the positive electrode substantially at the predetermined optimum position Thus I have shown in the drawings a lamp it com 'sing a housing |i containing a platform 22 on ,hich are mounted a positive supporting and feeding mechanism 25; carrying a positive electrode 21, and a negative electrode supporting and feeding mechanism 36 carrying a negative electrode 3| disposed approximately iorty 2| and between which and the positive electrode 2| occurs the arc resulting in the emission of light particularly from the crater 22 at the forward end of the positive electrode 2|.

In the present instance the light emitted particularly from the crater 22 of the positive electrode 2|, is directed by a reflector l3 to a lens or lenses, not shown, located in a cone 4 extending from the front end of the lamp I9, and there fore the electrode mechanisms 20 and 30 are operated and controlled to maintain proper spacing of the electrodes and thus proper quality of the arc, and to maintain the crater 22 of the positive electrode 2| substantially in the predetermined position of proper optical coordination with the reflector I3.

In the described embodiment the positive electrode mechanism 25 comprises three rollers 23, rotated to effect rotation of the positive electrode 2| to cause the electrode 2| to burn evenly, and skewed to simultaneously effect appropriate longitudinal movement of the electrode 2|, and the negative electrode mechanism 33 comprises a reciprocable electrode holder 32 carrying the negative electrode 3| and reciprocable by means of a suitable screw 33.

As indicated particularly in Figure 2, in the present embodiment the positive electrode rollers 23 are driven from a positive electrode drive shaft 24 operated by a positive electrode feed motor 25 through a suitable speed reduction mechanism 26 and a clutch 21 provided to permit adjustment of the positive electrode 2| by operation of a suitable hand crank 28, and similarly the negative electrode screw 33 is driven from a positive electrode drive shaft 3% operated by a negative electrode motor 35 through a suitable speed reduction mechanism 35 and a clutch 31 provided to permit adjustment of the negative electrode 3| by operation of a suitable hand crank 38.

Further, as indicated in Figure 3, in the pres" ent embodiment the positive electrode 2| is sup plied by a main positive conductor 4!) extending to a main positive terminal 4|, the negative electrode 3| is supplied by a main negative conductor 5|) extending to a main negative terminal 5| the positive electrode feed motor 25 comprises an armature 42 connected directly across the main positive and negative conductors E3 and 5!! and a field 43 connected across the main conductors 46 and 53 in series with an adjustable rheostat 44 and a control resistor 55, and the negative A 3 electrode feed motor 35 comprises an armature 52 connected directly across the main conductors 453 and and a field 53 connected across the conductors 5i and in series with an adjust able rheostat 55. and a control resistor 55.

With the foregoing the lamp comprises means responsive to the position of the crater 22 of the positive electrode 2|, normally shunting the negative control resistor 55, but operating upon movement of the crater 22 into position in advance of the correct optical location, to no longer shunt the negative control resistor 55, and to shunt the positive control resistor 45, thereby strengthening the positive motor field 43 and decreasing the speed of the positive motor 25 and the rate of feed of the positive electrode 2|, thus to restore the crater 22 to its proper location, and simultaneously weakening the negative motor field 53 and increasing the speed of the negative motor 35 and the rate of feed. or the negative electrode 3 thus nevertheless to maintain proper spacing of the electrodes 2| and 3| and proper quality of the arc.

According to my present preference the above means comprises an electromagnetic switch 5B of suitable construction, a light-responsive device ll! of the type shown in my copencling application Serial Number 157,575, filed April 22, 1950, and a lens i5 arranged to direct light from the crater 22 to the device H3.

Specifically the present switch 85 comprises a contact 5i connected to the positive motor field circuit ahead of the positive control resistor (55, a contact 62 connected to the negative motor field circuit ahead of the negative control resistor 55, a contactor 63 connected to the return from the control resistors 45 and 55 and biased to be normally in engagement with the negative contact 52, thereby shunting the negative control resistor 55, and an operating coil 64 energized under control of the device is and constructed and arranged thereupon to move the contactor 63 from the contact to the contact 6| and thereby transfer the shunt from the negative control resistor 55 to the positive control resistor 45.

Similarly the herein illustrated light-responsive device 55 comprises a base 7| provided with terminal pins l2 and 13, a glass bulb 14 closed to the base '23 and provided with a coating I5 relatively impervious to light but containing a window and a bi-metallic element "i1 carried by the one terminal pin comprising a forwardly extending arm Tia, a substantially inflexible cross-piece ill), and a reversely extending arm lie carrying a contact 18 arranged to engage a relatively stationary cooperating contact 19 carried by the other terminal pin 13.

With the foregoing the parts are so constructed and arranged that when the crater 22 of the positive electrode 2i is substantially at its optimum location, light from the crater 22 to the lens |5 will fall upon the forwardly extending arm Tia of the bi-metallic member 11, heating that arm and causing that arm to flex, resulting in moving and holding the member contact 18 away from and out of engagement with the cooperating contact 19.

On the other hand, when the crater 22 becomes appreciably in advance of its optimum location, the light to the lens l5 will then fall on the reversely extending arm He, heating that arm and causing that arm to flex, resulting in moving the member contact 78 into engagement with the cooperating contact 19, thus energizing the coil 64 of the electromagnetic switch 60,

resulting in decreasing the speed of the positive motor 25 and the rate of feed of the positive electrode 2|, and in commensurately increasing the speed of the negative motor and the rate of feed of the negative electrode 3|.

In the present embodiment a resistor I6 is connected across the terminals of the light-responsive device 15 for the purpose of decreasing arcing when the free end 18 of the element ll breaks engagement with the cooperating contact 15, and a signal lamp 5? is connected across a resistor i8 interposed in the connection from the negative switch contact 52, thereby to be energized when the switch 60 is in normal position and not energized when the switch 50 is in the alternate position, thus to visually indicate the condition of the apparatus.

As herein shown the foregoing electrical connections are accomplished by a conductor 88 extending from the main positive conductor to one terminal of the positive motor armature 42, one terminal of the positive motor field 43, one terminal or" the negative motor armature 52, and one terminal of the negative motor field 53, a conductor 8| extending from the other terminal of the positive motor field 43 to the movable contact of the positive adjusting rheostat a conductor 82 extending from the second terminal of the negative motor field 53 to the movable contact of the negative adjusting rheostat 54, a conductor 83 extending from the fixed terminal of the positive adjusting rheostat 44 to one terminal of the positive control resistor 45 and to the positive contact 5| of the switch Ell, a conductor 84 extending from the fixed terminal of the negative adjusting rheostat 54 to one terminal of the negative control resistor 55 and to one terminal of the lamp resistor I8, a conductor extending from the terminal of the resistor Hi to one terminal of the signal lamp il, a conductor 86 extending from the other terminal of the lamp I! to the second terminal of the resistor I8, a conductor 87 extending from the second terminal of the resistor Hi to the negative contact 62 of the switch 50, a conductor 88 extending from the main positive conductor 40 to the terminal pin 12 of the light-responsive device 15 and to one terminal of the shunting resistor l5, a conductor 89 extending from the other terminal of the resistor It and the terminal pin 73 of the device 10, to one terminal of the coil 64 of the switch 60, and a return conductor 90 connecting to the main negative conductor 5|] the second terminal of the positive motor armature 42, the second terminal of the positive control resistor 45, the second terminal of the switch control resistor 45, the second terminal of the switch coil 64, the contactor 63 of the switch 60. the second terminal of the negative control resistor 55, and the second terminal of the negative motor armature 52.

With the above arrangement the positive adjusting rheostat 44 is set to the position whereby with the switch 65 in normal position the positive electrode 2| will be fed at a rate slightly greater than the rate at which it is to be consumed, and the negative adjusting rheostat 54 is set to provide that the negative electrode 3| will be fed at a rate to maintain proper spacing of the electrodes and proper quality of the arc.

Under these conditions, the crater 22 of the positive electrode 2i will be gradually advanced beyond its predetermined location; however, before this advance has become sufiicient to affect proper optical coordination of the crater 22 with the remainder of the optical system, the light from the crater 22 to the lens I5 will become transferred from the forwardly extending arm 11a to the reversely extending arm Ho of the bi-metallic element 11, resulting in engagement of the element contact 18 with the cooperating contact i9, closing the circuit through the coil 54 of the electromagnetic switch 60, and shifting the electromagnetic contactor 63 from engagement with the negative contact 62 to engagement with the positive contact 6|, transferring the shunt from the negative control resistor 55 to the positive control resistor 45.

The control resistors and 5-5 being of proper values, thereupon the positive electrode 2| will be fed at a rate slightly less than the rate at which it is being consumed, and the negative electrode 3! will be fed at a rate greater than the rate at which it is being consumed, and such that the combined rates of feed of the two electrodes 2i and 3: continue to be equal to the combined rate at which they are being consumed and thus the quality of the arc continues to be maintained.

Thereby the crater 22 will gradually recede to the predetermined point, whereupon the lens i5 will no longer direct light upon the reversely extending arm Tie, the element contact 18 will withdraw from engagement with the cooperating contact 1-79, the circuit through the switch coil will operate to automatically maintain both the quality of the arc and the are at the proper location.

However, within any usual limits of variation of rate of feed of the positive electrode 2!, the corresponding variation in the rate of feed of the negative electrode 31 is less than the amount by which the rate of feed of the negative electrode may be satisfactorily varied at each cycle of the automatic variation by operation of the switch and its associated mechanisms.

Thus under normal circumstances it is not necessary to adjust the rate of feed of the nega tive electrode 31 consequent to adjustment of the rate of feed of the positive electrode 2i, and

therefore in the present embodiment the negative control resistor is constructed of proper value, and for automatic operation of the lamp the negative resistor is set and remains at zero.

Thus the only adjustment is of the positive adjusting rheostat 5 1, according to the rate at which the positive electrode 2| is to be consumed, and further, the rheostat 6 be scaled directly, either in terms of rate of consumption of the positive electrode, or in terms of the corresponding currents, or however may be desired.

Therefore the described embodiment adequately accomplishes at least the principal object of my invention, and on the other hand, obviously various changes and modifications may be made, and therefore my invention is not to be regarded as limited to the particular embodiment herein shown and described, and I claim as my invention:

1. An arc lamp comprising two electrodes constructed and arranged to function as terminals 6 I of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, capable of change of the ratio between the respective rates of feed, and comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first resistance connected to alter the speed of the first motor, a second resistance connected to alter the speed of said second motor, and an electric switch normally rendering said first resistance operative and not said second resistance, movable to a position rendering said second resistance operative and not said first resistance, and means constructed and arranged to automatically shift said switch responsive to change in position of the arc.

2. An are lamp comprising two electrodes constructed and arranged to function as terminals of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, adjustable to change the rate of feed of one of said electrodes, capable of change of the ratio between the respective rates of feed, and comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first resistance connected to alter the speed of said first motor, a second resistance connected to alter the speed of said second motor, and an electric switch normally rendering said first resistance operative and not said second resistance, movable to a position rendering said second resistance operative and not said first resistance,

and means constructed and arranged to automatically shift said switch responsive to change in position of the are.

3. An are lamp comprising two electrodes constructed and arranged to function as terminals of an are, means constructed and arranged to automatically and continuously feed said electrodes substantially at the rate at which said electrodes will be consumed at the current at which the lamp is desired to be operated, thereby to automatically maintain the quality of the arc, and to normally feed said electrodes at respective rates defining a ratio somewhat different from the ratio at which said electrodes will be consumed at such current, and capable of change of said ratio to a ratio also somewhat different from the ratio at which said electrodes will be consumed at such current but departing in the inverse direction, said means comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first resistance connected to alter the speed of said first motor from the speed of the first said ratios to the speed of the second said ratios, a second resistance connected to alter the speed of said second motor from the speed of the second said ratio to the speed of the first said ratio, an electric switch normally rendering said first resistance operative and not said second resistance, movable to a position rendering said second resistance operative and not said first resistance, and means constructed and arranged to automatically shift said switch responsive to change in position of the arc.

4. An arc lamp comprising two electrodes constructed and arranged to function as terminals of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, and means nemesis.

constructed and arranged to automatically maintain the arc substanially at a given position, said means comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first resistance connected to alter the speed of said first motor, a second resistance connected to alter the speed of said second motor, and an electric switch normally rendering said first resistance operative and not said second resistance, movable to a position rendering said second resistance operative and not said first resistance, and means constructed and arranged to automatically shift said switch responsive to change in position of the arc.

5. An arc lamp to operate on direct current, comprising a positive electrode and a negative electrode constructed and arranged to form the terminals of an are, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, capable of change of the ratio between the respective rates of feed, and comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first resistance connected to alter the speed of said first motor, a second resistance connected to alter the speed of said second motor, and an electric switch normally rendering said first resistance operative and not said second resistance, movable to a position rendering said second resistance operative and not said first resistance, and means constructed and arranged to automatically shift said SiltCh responsive to change in position of the arc and thereby to automatically maintain the arc substantially at a given position.

6. An arc lamp comprising two electrodes constructed and arranged to function as terminals of an are, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, capable of change of the ratio between the respective rates of feed, and comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first resistance in series with the field of said first motor, a second resistance in series with the field of said second motor, and an electric switch normally shunting said first resistance and not said second resistance, movable to a position shunting said second resistance and not said first resistance, and means constructed and arranged to automatically shift said switch responsive to change in position of the arc.

7. An arc lamp comprising two electrodes constructed and arranged to function as terminals of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, adjustable to change said rate, capable of change of the ratio between the respective rates of feed, and comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first rheostat connected to adjust the speed of said first motor, a second rheostat connected to adjust the speed of said second motor, a first resistance connected to alter such speed of said first motor, a second resistance connected to alter such speed of said second motor,

and an electric switch normally rendering said first resistance operative and not said second resistance, movable to a position rendering said second resistance operative and not said first resistance, and means constructed and arranged to automatically shift said switch responsive to change in position of the arc.

8. An arc lamp comprising two electrodes constructed and arranged to function as terminals of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, adjustable to change said rate, capable of change of the ratio between the respective rates of feed, and comprising a first electric motor connected to continuously feed one of said electrodes, a second electric motor connected to continuously feed the other of said electrodes, a first rheostat connected to adjust the speed of said first motor, a first resistance in series with the field of said first motor, a second resistance in series with the field of said second motor, and an electric switch normally shunting said first resistance and not said second resistance, movable to a position shunting said second resistance and not said first resistance, and mean constructed and arranged to automatically shift said switch responsive to change in position of the are.

9. An arc lamp comprising two electrodes constructed and arranged to function as terminals of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, a single means operative to adjust the rate at which said electrodes will be consumed, and means constructed and arranged to automatically maintain the are substantially at a given position at any rate at which said electrodes are adjusted to be consumed.

10. An arc lamp comprising two electrodes constructed and arranged to function as terminals of an are, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate and capable of change of the ratio between the respective rates of feed, and means constructed and arranged. to automatically change said ratio in response to change in position of the arc.

11. An arc lamp comprising two electrodes constructed and arranged to function as ter minals of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, adjustable to change said rate, and capable of change of the ratio between the respective rates of feed, and means constructed and arranged to automatically change said ratio in response to change in position of the arc and thereby to automatically maintain the arc substantially at a given position.

12. An arc lamp comprising two electrodes constructed and arranged to function as terminals of an arc, means constructed and arranged to automatically and continuously feed said electrodes each at a substantially constant rate, and means constructed and arranged to automatically maintain the are substantially at a given position.

13. An arc lamp and control therefor includmg, in combination, two electrodes supported for relative movement, means for automatically feeding each of said electrodes at a substantially constant rate and capable of change of ratio between the respective rates of feed, said feeding means including a first electric motor adapted to continuously feed one of said electrodes, a second electric motor adapted to continuously feed the other of said electrodes, a first resistance connected to alter the speed of the first motor, a second resistance connected to alter the speed of the second motor, a shunt resistor connected with one of the resistances, switch means movable to a position for connecting the shunt resistor to the other of said resistances, and means responsive to the relative position of one of said electrodes for automatically actuating said switch.

14. An arc lamp and control therefor including, in combination, two electrodes supported for relative movement, means for automatically feeding each of said electrodes at a substantially constant rate and capable of change of ratio between the respective rates of feed, said feeding means including a first electric motor adapted to continuously feed one of said electrodes, a second electric motor adapted to continuously feed the other of said electrodes, a first resistance connected to alter the speed of the first motor, a second resistance connected to alter the speed of the second motor, a shunt resistor connected with one of the resistances, electrically actuated switch means movable to a position for connecting the shunt resistor with the other of said resistances to effect a change in rates of speed of the electrode feed motors, and energyresponsive means intercalated in the switch-actuating circuit to cause actuation of the switch upon change in position of the arc.

15. An arc lamp and control therefor including, in combination, two electrodes supported for relative movement, means for automatically feeding each of said electrodes at a substantially constant rate and capable of change of ratio between the respective rates of feed, said feeding means including a first electric motor adapted to continuously feed one of said electrodes, a second electric motor adapted to continuously feed the other of said electrodes, a first resistance connected to alter the speed of the first motor, a second resistance connected to alter the speed of the second motor, a shunt resistor connected with one of the resistances, said resistances in the motor circuits and said shunt resistor being arranged to maintain a constant combined rate of speed of said motors, electrically actuated switch means movable to a position for connecting the shunt resistor with the other of said resistances to increase the speed of one motor and decrease the speed of the other, and energy-responsive means intercalated in the switch-actuating circuit to cause actuation of the switch dependent upon the relative position of the arc.

ARTHUR J. HATCH.

References Cited in the file of this patent UNITED STATES PATENTS Number 

